(10) باب وَضْعِ الْمَاءِ عِنْدَ الْخَلاَءِ
Narrated Ibn `Abbas:
Once the Prophet (ﷺ) entered a lavatory and I placed water for his ablution. He asked, "Who placed it?" He was informed accordingly and so he said, "O Allah! Make him (Ibn `Abbas) a learned scholar in religion (Islam).
Reference: Sahih al-Bukhari 143
In-book reference: Book 4, Hadith 9
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 4, Hadith 145